Mobile technologies and consumer electronic devices (CED) continue to expand in use and scope throughout the world. In parallel with continued proliferation, there is rapid technical advance of device hardware and components, leading to increased computing capability and incorporation of new peripherals onboard a device along with reductions in device size, power consumption, etc. Most devices, such as mobile phones, tablets, and laptops, include audio communication systems and particularly one or more speakers to interact with and/or stream audio data to a user.
Every device has an acoustic signature, meaning the audible characteristics of a device dictated by its makeup and design that influence the sound generated by the device or the way it interacts with sound. The acoustic signature may include a range of nonlinear aspects, which potentially depend on the design of the device, on the age of the device, the content of an associated stream (e.g., sound pressure level, spectrum, etc.), and/or the environment in which the device operates. The acoustic signature of the device may significantly influence the audio experience of a user.
Improved acoustic performance may be achieved, generally with additional cost, increased computational complexity, and/or increased component size. Such aspects are in conflict with the current design trend. As such, cost, computation, and size sensitive approaches to addressing nonlinear acoustic signatures of devices would be a welcome addition to a designer's toolbox.
Tuning is generally performed during design and validation of a new handset. Tuning is performed by testing the new handset on a range of ear simulators, as well as head and torso simulators, and the tuning process is directed by a series of standard performance levels. Such simulators are static and rarely reflective of actual operating conditions of the handset in the real world.
In real world conditions, the actual acoustic impedance between a handset receiver and the ear of a subject may change dramatically based on position, quality of the seal against the ear, physiology of the ear, hair coverage around the ear, clothing worn around the head of the subject, jewelry worn on the ear of the subject, ear modifications, environmental conditions, and the like.
There is a need for improving perceived sound quality from a handset in real world settings.